StackFrameDepth should be managed per ThreadHeap

third_party/WebKit/Source/platform/heap/StackFrameDepth.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef StackFrameDepth_h
 #define StackFrameDepth_h
 
 #include "platform/PlatformExport.h"
 #include "wtf/Allocator.h"
 #include "wtf/Assertions.h"
 #include <cstddef>
 #include <stdint.h>
 
 namespace blink {
 
 // StackFrameDepth keeps track of current call stack frame depth.
 // It is specifically used to control stack usage while tracing
 // the object graph during a GC.
 //
 // Use isSafeToRecurse() to determine if it is safe to consume
 // more stack by invoking another recursive call.
 class PLATFORM_EXPORT StackFrameDepth final {

[haraken, 2016/09/02 09:07:57]

Add DISALLOW_NEW().

-    STATIC_ONLY(StackFrameDepth);
 public:
-    inline static bool isSafeToRecurse()
+    bool isSafeToRecurse()
     {
         // Asssume that the stack grows towards lower addresses, which
         // all the ABIs currently supported do.
         //
         // A unit test checks that the assumption holds for a target
         // (HeapTest.StackGrowthDirection.)
-        return currentStackFrame() > s_stackFrameLimit;
+        return currentStackFrame() > m_stackFrameLimit;
     }
 
-    static void enableStackLimit();
-    static void disableStackLimit()
+    void enableStackLimit();
+    void disableStackLimit()
     {
-        s_stackFrameLimit = kMinimumStackLimit;
+        m_stackFrameLimit = kMinimumStackLimit;
     }
 
 #if ENABLE(ASSERT)
-    inline static bool isEnabled() { return s_stackFrameLimit != kMinimumStackLimit; }
-    inline static bool isAcceptableStackUse()
+    bool isEnabled() { return m_stackFrameLimit != kMinimumStackLimit; }
+    bool isAcceptableStackUse()
     {
 #if defined(ADDRESS_SANITIZER)
         // ASan adds extra stack usage leading to too noisy asserts.
         return true;
 #else
         return !isEnabled() || isSafeToRecurse();
 #endif
     }
 #endif
 
@@ skipping 28 matching lines @@
     static const int kSafeStackFrameSize = 32 * 1024;
 
     // The stack pointer is assumed to grow towards lower addresses;
     // |kMinimumStackLimit| then being the limit that a stack
     // pointer will always exceed.
     static const uintptr_t kMinimumStackLimit = ~0ul;
 
     static uintptr_t getFallbackStackLimit();
 
     // The (pointer-valued) stack limit.
-    static uintptr_t s_stackFrameLimit;
+    uintptr_t m_stackFrameLimit;
 };
 
 class StackFrameDepthScope {

[haraken, 2016/09/02 09:07:57]

Conceptually StackFrameDepthScope should be equal to the scope of Visitor. It
may be better to move the contents of StackFrameDepthScope to Visitor and remove
StackFrameDepthScope.

[keishi, 2016/09/06 12:54:22]

Done.

     STACK_ALLOCATED();
     WTF_MAKE_NONCOPYABLE(StackFrameDepthScope);
 public:
-    StackFrameDepthScope()
+    StackFrameDepthScope(StackFrameDepth* depth): m_depth(depth)

[haraken, 2016/09/02 09:07:57]

Add explicit.

[keishi, 2016/09/06 12:54:22]

Done.

     {
-        StackFrameDepth::enableStackLimit();
+        m_depth->enableStackLimit();
         // Enabled unless under stack pressure.
-        ASSERT(StackFrameDepth::isSafeToRecurse() || !StackFrameDepth::isEnabled());
+        DCHECK(m_depth->isSafeToRecurse() || !m_depth->isEnabled());
     }
 
     ~StackFrameDepthScope()
     {
-        StackFrameDepth::disableStackLimit();
+        m_depth->disableStackLimit();
     }
+
+private:
+    StackFrameDepth* m_depth;
 };
 
 } // namespace blink
 
 #endif // StackFrameDepth_h